1. Field of the Invention
The present invention relates to a specimen sampling device for the collection of microbiological biopsy specimen from a body cavity and, more particularly, relates to a device which incorporates a cytology brush which is readily introducible into the biopsy channel of an endoscope. In particular, the cytology brush is especially adapted for brushing and thereby obtaining microbiological biopsy specimen from areas of the gastrointestinal tract which are difficult to reach. Pursuant to another important aspect of the invention, the specimen sampling device incorporating the gastrointestinal cytology brush is of simple and inexpensive yet sturdy and reliably operable construction so at to render the brush readily disposable in a highly economical manner after only a single use.
Although numerous and widely varied types of biopsy specimen sampling devices for collecting microbiological specimen are currently known in the medical technology, particularly in conjunction with their use in endoscopes, these are either of generally complicated constructions which necessitate the manufacture and assembly of highly expensively produced components or; alternatively, are of such simple construction as to lack the sophistication and strength to enable them to be satisfactorily operated for their intended purposes. Thus, in particular, cytology brushes which are introduced into body cavities through endoscopes for the brushing and removal of microbiological biopsy samples from gastrointestinal tracts are subject to a number of limitations and disadvantages as currently employed in the state-of-the-technology.
Hereby, pursuant to a specific construction of a cytology brush as presently utilized for the obtaining of microbiological biopsy specimen, the structure of the sampling device incorporates an elongated flexible plastic tubing forming a sheath insertable into the biopsy channel of an endoscope, through which an operating wire is conducted from a proximal end mounting structure for effectuating longitudinal and rotational movement of the wire within the flexible sheath, and at a distal end of the sheath the wire has a cytology brush mounted thereon consisting of nylon bristles which, when the brush is extended outwardly beyond the distal end of the sheath is adapted to brush over and obtain microbiological biopsy specimen from the body cavity of a patient. Thereafter, the cytology brush with the microbiological biopsy specimen entrained in the bristles is withdrawn into the distal end of the plastic sheath, and the entire sampling device withdrawn from the body cavity through the endoscope. This type of construction, in which the outer diameter of the bristles of the cytology brush is dimensioned to be slightly larger than the internal diameter of the plastic sheath causes the brush bristles to assume a bend deviating from a radial orientation, and moreover, when retracted into the distal end of the sheath after obtaining the biopsy specimen, to be subject to some further bending of the extended bristles which may cause some of the entrained microbiological biopsy matter to be sprayed outwardly into the body cavity so as to become a source of infection in the patient. Moreover, when the cytology brush is extended from the distal end of the plastic sheath subsequent to withdrawal of the device from the endoscope in order to be able to examine the biopsy specimen, the exposure of bristles of the cytology brush may cause the bristles to expand and possibly spray out some biopsy matter entrained therein, thereby contaminating the laboratory and the analyzing personnel. Additionally, a cytology brush which has the outer plastic tubing sheath constructed from only a single tubing member and with a central wire is frequently subject to kinking when inserted into an endoscope, and moreover, rotation of the operating wire mounting the brush at its distal end becomes rather difficult and cannot be satisfactorily implemented in a controlled manner.
2. Discussion of the Prior Art
Although various attempts have been made which are intended to overcome difficulties encountered in the state-of-the-art as represented by the foregoing type of construction of a cytology brush, it is still subject to various disadvantages and drawbacks.
Abele, et al. U.S. Pat. No. 4,235,244 discloses a microbiological specimen sampling device which has a cytology brush mounted at the distal end of an operating wire adapted to be longitudinally displaced within a tubular plastic member. A second outer sleeve is mounted over the tubular plastic member and extends some distance beyond the leading or distal end which is adapted to be inserted through an endoscope into a body cavity, and which retains a plug which will protect the specimen sampling brush from contamination during introduction into the body cavity and is adapted to be ejected upon being pushed outwardly by an extending sampling brush. In this particular instance, the brush which is contained within the inner sleeve tubing is subject to the disadvantages of having its bristles bent and radially compressed, and thereafter expanded when pushed outwardly through the larger diameter section into the body cavity, and subsequent to obtaining microbiological biopsy specimen being again compressed when entering the inner tubular member upon retraction.
MacLean U.S. Pat. No. 2,955,592 discloses a diagnostic instrument which has a brush adapted to be inserted into a body cavity, and to be able to obtain microbiological biopsy samples for analysis. There is no disclosure of the brush being arranged in a specimen sampling device analogous to that contemplated by the present invention, particularly as described hereinbelow in more extensive detail.
Similarly, Tsukagoshi U.S. Pat. No. 4,936,312 discloses a body cavity inserting instrument having a brush for picking up and retaining microbiological samples which is attached to an operating wire enclosed within a helically-coiled outer sheathing. Also in this instance, there is no disclosure of the brush being extended and thereafter retracted after obtaining microbiological samples in a manner contemplated by the present invention.